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This coding exercise comes from Upcase, the online learning platform we run. It's part of the Advanced ActiveRecord Querying course and is just one small sample of all the great material available on Upcase, so be sure to visit and check out the rest.
In this exercise, you'll write custom joins to write queries that ActiveRecord can't infer on its own.
To start, you'll want to clone and run the setup script for the repo
git clone [email protected]:thoughtbot-upcase-exercises/custom-joins.git
cd custom-joins
bin/setup
After cloning and running bin/setup:
- Edit
db/schema.rbto get a sense of the database schema you'll be querying. - Take a look at the classes in
app/modelsto get familiar with the models and associations you'll be working with. - Edit
spec/models/person_spec.rband remove thependingline from the spec. - Edit
app/models/person.rband implementwithout_remote_managerto get the spec passing. - Edit
spec/models/person_spec.rband remove the otherpendingline. - Edit
app/models/person.rbagain and rewritewith_employeesandwith_local_coworkersto make the spec pass.
You can run rake to re-run the tests at any time.
Once all the tests are passing (and there are no pending specs), you're all set!
Watch the trail video on using custom joins and check out the documentation for joins.
Check out the featured solution branch to see the approach we recommend for this exercise.
If you find yourself stuck, be sure to check out the associated Upcase Forum discussion for this exercise to see what other folks have said.
When you've finished the exercise, head on back to the Advanced ActiveRecord Querying course to find the next exercise, or explore any of the other great content on Upcase.
custom-joins is Copyright © 2015-2018 thoughtbot, inc. It is free software, and may be redistributed under the terms specified in the LICENSE file.
This exercise is maintained and funded by thoughtbot, inc.
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